programming-encapsulation

Programming Encapsulation

• To program encapsulation, you should already have a solid understanding of what encapsulation in Object Oriented Programming (OOP) is.

How do you Define Encapsulation?

Get Methods

• The “get” method is a common naming convention for a type of method that is used to retrieve the value of an object’s private attributes (instance variables).

• These methods are also known as “getter” methods or “accessor” methods.

• The main purpose of a get method is to provide controlled access to the internal state (data) of an object without allowing direct modification.

• Attributes are often declared as private to achieve encapsulation, so cannot be accessed directly from outside the class.

• External code can use the public get methods to read the values of these private attributes (also known as instance variables).

Pseudocode

Pseudocode for a get method

 

Java

//creating a class called NumberUpdater

public class NumberUpdater {

//setting the private attribute to the value of 10

private int number = 10;

//creating a get method that will return the value store in the number attribute

public int getNumber() {

return number;

}

}

 

Python

#creating a class called NumberUpdater

class NumberUpdater:

#setting the private attribute to the value of 10 

def __init__(self):

self.__number = 10

#creating a get method that will return the value stored in the number attribute

@property

def number(self):

return self.__number

Set Methods

• The “set” method is a common naming convention for a type of method that is used to set the value of object’s private instance variables.

• Setter methods, also known as “setter” methods or “mutator” methods

• Generally additional code is written within the method to allow controlled access by enforcing certain conditions or validations before updating the attribute

Pseudocode

 

Pseudocode for a “setter” method

 

 

Java

//creating a class called NumberUpdater

public class NumberUpdater

//setting attribute value to 10

private int oldnumber = 10;

//creating a set method

public void setNumber(int newnumber) {

//if the new number is less than zero

if (newnumber < 0) {

//oldnumber is kept the same 

oldnumber = oldnumber;

} else {

//oldnumber is updated with the new number value

oldnumber = newnumber;

}

}

}

 

 

 

Python

 

//creating a class called NumberUpdater

class NumberUpdater:

//setting attribute value to 10

def __init__(self):

self.__oldnumber = 10

 

//creating a set method 

def setNumber(self, newnumber):

//if the new number is less than zero 

if newnumber < 0:

//oldnumber is kept the same

self.__oldnumber = self.__oldnumber

else:

//oldnumber is updated with the new number value

self.__oldnumber = newnumber